This invention relates generally to methods for assembling a set of defining parameters relating to certain physical characteristics of a gemstone and, more particularly, to a method of identifying and specifying the total colored appearance of a gemstone in an objective and independently repeatable manner.
A major difficulty frequently encountered by those professionally or personally involved with the handling of colored gemstones--such as gem dealers, jewelers and gemologists--is the almost totally subjective manner in which the overall colored appearance of such stones is typically described. Color names are most often assigned to a particular stone to enhance its merchantability rather than for the purpose of objectively specifying its appearance within the framework of an accurate and independently verifiable set of characteristic parameters. Some color designations common in the gem trade are merely intended to subliminally suggest a particular mood and can thus denote a wide range of shading or tints--such as blushing rose, glowing coral, azure blue and forest green. Even that nomenclature said to identify standard colors for particular stones--such as angel skin or ox blood for coral, pigeon blood for ruby, apple green for jade, and grass green or leaf green for emerald--in fact corresponds to varied shades or tints for different people whose individual experiences tend to affect their own interpretations.
The common use of these highly subjective terms to describe the color of gemstones frustrates the desire of a jeweler or gemmologist to best serve the customer. When a stone is lost, the ability to recognize and obtain a replacement stone of suitably close color match to the original is practically impossible absent direct comparison with a companion stone from the same article of jewelry. A uniform system of color grading would permit ready replacement of a lost gemstone with one practically identical in overall color characteristics and appearance, without the need to directly examine companion pieces or stones. A gem dealer could also better advise a customer in connection with new purchases by retaining a listing of parameters and values providing an objective and repeatable indication of the color of gemstones already owned by the customer.